The present invention relates generally to adjusters which are used to adjust the aim of a vehicle lamp. Specifically, this invention relates to a motorized adjuster used to adjust the aim of a vehicle lamp.
Vehicles such as automobiles typically have several lamps including headlamps and fog lamps. These lamps generally comprise a reflector sealed to a lens with a bulb therein. These lamps are securely fit into mounting brackets. The lamps are usually pivotally engaged to the mounting bracket at a plurality of points. The mounting brackets are attached to the vehicle. Together, a lamp and a mounting bracket form a complete lamp assembly. Once the lamp assembly has been manufactured and installed into a vehicle, the aim of the lamp must be adjusted to comply with federal and state regulations. As a result of accidents, maintenance, and normal vibrations and wear, the aim of the lamp must be occasionally adjusted during the lifetime of the vehicle.
One method of adjusting the aim of the lamp involves using an adjuster. The adjuster may be formed as part of the mounting bracket or may be a separate part that communicates with both the lamp and the mounting bracket. One known type of adjuster comprises a housing and a control rod extending there from. The control rod is engaged to lamp. Actuation or operation of the adjuster causes the control rod to move with respect to the lamp assembly. Such movement causes the lamp to pivot with respect to the mounting bracket, thereby affecting the aim of the lamp.
One example of this type of adjuster, such as the one disclosed in U.S. Pat. No. 6,257,747 to Burton, requires manual operation. The housing of the adjuster has an opening and a gear positioned inside the housing. The gear is functionally engaged to the control rod. A driver is inserted into the opening and interacts with the gear. Actuation of the driver results in rotation of the gear and engaged control rod. The gear translates actuation of the driver into movement of the control rod. Numerous variations and improvements exist on this concept.
A manual adjuster has limited applicability. Many countries, including most of Europe, require a driver to be able to adjust the aim of a vehicle's lamps from inside the cabin. Additionally, luxury vehicles are now offering lamps that track and illuminate the direction of the vehicle or that adjusts the aim of the lamp to compensate for the pitch of the road or weight of the vehicle (i.e. driving on hilly terrain or with a heavy load in the vehicle). The aim of the lamp is automatically adjusted as the steering wheel is turned or as a result of the relative pitch of the suspension. A computer coordinates the degree of turn of the steering wheel, the speed of the vehicle, and/or the pitch of the suspension with the aim of the lamps. This coordination requires a high degree of precision. A driver cannot safely turn a steering wheel and manually adjust the aim of the vehicle's lamps at the same time.
A number of motorized lamp adjusters have been developed to provide improved functionality. Many of these adjusters provide for both manual and motorized operation. In practice, the adjusters are manually operated to aim the lamp during manufacture, maintenance, and repair of the vehicle. The adjusters rely on motorized operation to aim the lamp while the vehicle is on the road. These adjusters can be connected to control units that provide for automatic adjustments while the vehicle is driven. Examples of such adjusters are disclosed in U.S. Pat. No. 5,394,318 to Komachi; U.S. Pat. No. 5,673,991 to Eickhoff et al.; and U.S. Pat. No. 6,012,829 to Natchoo. These adjusters all use an electric motor to longitudinally move a control rod. The motors are offset from the control rod and located inside the adjuster housing. These adjusters rely on a series of gears, speed reducers, circuits, potential meters, and transmissions to translate the power generated by the motor into longitudinal movement of the control rod. As such, these adjusters employ a series of parts. Each part must be separately manufactured. The parts are then assembled inside the housing to form the adjuster. Using multiple parts increases the potential for malfunction, breakage and general wearing of the adjuster. Further, using a series of parts results in a larger housing and thus a larger adjuster. Such an adjuster requires more space in a vehicle, thereby affecting the overall design and manufacture of the vehicle and making the overall cost of both the adjuster and the vehicle more expensive.
Accordingly, a need exists for an improved motorized lamp adjuster that solves these and other deficiencies in the prior art. Of course, the present invention may be used in a multitude of situations where similar performance capabilities are required.